Spectroscopic studies of D-α-tocopherol concentration-induced transformation in egg phosphatidylcholne vesicles

Abstract

Abstract:The effects of embedding up to 60 mol% of α-tocopherol (α-Toc) on the morphology and structure of the egg phosphatidylcholine (PC) membrane were studied using spectroscopic techniques. The resulting vesicles were subjected to turbidometric and dynamic light scattering measurements to evaluate their size distribution. The α-Toc intrinsic fluorescence and its quenching was used to estimate the tocopherol position in the membrane. Optical microscopy was used to visualize morphological changes in the vesicles during the inclusion of tocopherol into the 2 mg/ml PC membrane. The incorporation of up to 15 mol% of tocopherol molecules into PC vesicles is accompanied by a linear increase in the fluorescence intensity and the simultaneous formation of larger, multilamellar vesicles. Increasing the tocopherol concentration above 20 mol% induced structural and morphological changes leading to the disappearance of micrometer-sized vesicles and the formation of small unilamellar vesicles of size ranging from 30 to 120 nm, mixed micelles and non-lamellar structures.

Synergistic and antagonistic effects between alpha-tocopherol and phenolic acids in liposome system: spectroscopic study

“…Presence in vicinity of the other compound leads to changes in microenvironment of the DPH resulting in shortening of fluorescence lifetime proportional to degree of interactions between compounds and membrane structure. The shortest lifetime was noted for DPH in the presence of α-T (5.80 ns), which indicates that α-T incorporates near to hydrophobic part of PC membrane as shown in the other studies [18,19,24]. Among studied phenolic acids, the shortest fluorescence lifetime of DPH was obtained for sample containing FA.…”

“…According to our earlier studies [18,19], we assumed that α-T resides inside the hydrophilic phase of the membrane, whereas the phytyl chain is anchored in the hydrocarbon core. Such location of α-T has already been indicated also by other authors [20].…”

“…3. It shows the highest PCF values for α-T very probably due to the fact that α-T was embedded into the membrane interior [18,19,24], where effectively protects unsaturated fatty acids against oxidation. The PCF values of α-T were directly proportional to α-T concentration.…”

Composition of tocochromanols in the kernels recovered from plum pits: the impact of the varieties and species on the potential utility value for industrial application

“…Tocopherols, compared to tocotrienols, are intensively investigated in both human studies [16,17] and model systems [18][19][20]. The tocotrienols are linked with the great potential for preventing cancer, diabetes, cardiovascular and neurodegenerative diseases [16].…”

Tocopherol and tocotrienol contents in the sea buckthorn berry beverages in Baltic countries: Impact of the cultivar

“…Tocochromanols have been reported as strong lipophilic antioxidants in different model systems [17,33]. In order to determine and compare the antioxidant activity of studied sea buckthorn beverages a well-established and reliable DPPH assay was applied.…”